All the Magic We Cannot See
by Biana Delacroix
Summary: There is a room in the Ministry where the door is always locked, and the most powerful magic known to wizard is studied. Caroline and Klaus didn't know what they would start by going inside, but between red strings and dreams that aren't their own, there's something between them that no magic can explain.


**Author's Note: I wrote this for the wonderful and amazing Angie (Angelikah/thetourguidebarbie) who had asked for a Hogwarts AU with a side of Koroline friendship and it spiraled into this oneshot. It's everything I've ever been afraid to write, Harry Potter is sacred to me and I only hope I didn't completely tarnish the Wizarding World. Enjoy!**

* * *

If there was ever a time to harm a cat, this was it.

Caroline shifted uncomfortably, watching Mrs. Norris with narrowed eyes, wondering exactly how much trouble she would get in for using a hex on an animal. She could say she was practicing, NEWTs drove people to do weird things, but the chances of detention were too great, and she knew she couldn't afford to take the risk of losing house points, not when Slytherin were only a hundred away from taking lead.

Of course, she was already putting that lead in jeopardy just by being out after hours. One minute more and she was seriously considering leaving her post, but the reason for her vigil _finally_ made himself known with a short series of knocks on the wood panel behind her.

Caroline answered with four knocks of her own and the portrait of the first Wizengamot gently eased open, a grinning Kol Mikaelson slipping into the hallway and closing the entrance to the secret passage behind him.

"Miss me darling?"

Caroline huffed, slugging him in the arm and causing him to drop some of the Honeydukes merchandise he was laden with. "You _jerk,_ you were supposed to be back ten minutes ago!" she hissed, trying to remember that she couldn't yell at him as much as she wanted to. A full tirade would be saved for when they were back in the common room, but for now, she begrudgingly helped Kol pick up the spilt goods.

"I'd have been back faster but I had to search for the Fizzing Whizzbees that _somebody_ insisted on," he replied with a wink and Caroline groused but before she could snap back the hairs on her neck stood on edge. She snapped her head to the corner where Mrs. Norris had been watching and realized that the stupid cat had flown the scene ages ago. Which meant…

"Filch is going to be here _now,_ _"_ she warned, already moving into the shadows and following the well-worn path to the dungeon. Even as a seventh-year, Caroline was sure she didn't know all of Hogwarts' secrets, but getting to the Slytherin common room was something she could do blindfolded, especially from the third-floor passageway that Kol had started dragging her to sometime in the middle of their fourth year. It was at that point she seriously considered dissolving her friendship with Mikaelson, but he always brought back her favourite sweets, and Caroline knew that no matter how much she complained, it wouldn't feel right to let him go without playing lookout.

Didn't mean she couldn't complain though.

"I mean seriously, you do this at least twice a month, how do you still take forever?!" They'd made it down to the dungeons and finally felt safe enough to slow down and raise their voices to normal volume.

"Excuse me darling, but anytime you'd prefer to be the one navigating that passage in the dark, be my guest."

"You have a wand," Caroline muttered as they approached the stone-wall entrance.

" _Cornish Pixie,"_ Kol said, frowning when nothing happened. "Bloody hell, is it broken?"

Caroline rolled her eyes. "Do you ever read the message board? It changed three days ago. _Acromantula._ _"_ She smirked as the wall slid open but their bickering was cut short by the sudden noise of the party inside.

"Took you long enough!" Rebekah Mikaelson's shrill voice cut through the crowd as she pulled the bag of candy out of her older brother's hands. She didn't stop to chat before disappearing to find her dorm mates leaving an irate Kol in her wake.

"Lovely to see you too Bekah," he called after her, "What are you laughing at, Forbes?"

Caroline didn't bother trying to hide her sniggering, but they were interrupted by the rest of the Slytherin quidditch team hoisting Kol up onto their shoulders and starting a cheer which Caroline happily joined in on. A cup of Butterbeer was pressed into her hands and she let herself enjoy the party, rolling her eyes whenever someone mentioned how Kol was the 'best Beater they'd ever had.' As if she hadn't heard that since second-year. Eventually she dragged one of the leather couches over to one of the windows, close enough that she could feel the heat of the fire but watch the lake, keeping an eye out for the giant squid.

"Not enjoying the party in my honour?" Kol dragged his own chair next to hers, plopping down and offering her his bag of Bertie Bott's Every Flavour Beans.

"Last I checked, it was the _entire_ team that beat Hufflepuff," Caroline said dryly, taking a handful of beans and inspecting them carefully. "Any anyway why aren't you over there with your admirers?" she asked, nodding towards the sixth-year girls who were glancing over at Kol ever few seconds. Rebekah stood among them, pretending to gag.

"Bet you're going to be glad when we have this place to ourselves for Easter," Caroline remarked, already envisioning the peace and quiet.

Kol pulled a strange face. "Here's the thing Forbes…Mother Dearest is calling me back to the nest."

Caroline dropped her jellybeans, aghast. "What?! But we were supposed to spend the week studying for NEWTs!"

"You don't have to tell me that, it didn't work on her," Kol grumbled, rolling his eyes.

"She never used to make you come home this much."

"She's been depressed ever since Henrik started here."

Caroline crossed her arms, sinking down into the comfortable leather and pouted, mourning the loss of her study partner. "Well I hope you know I have to rethink my entire study plan. It was made for two people to revise together."

Kol mulled over her words before a slow, sinister smile spread across his face. "I mean…you don't _have_ to spend the holidays here, alone."

"What? Kol, I can't go home, I already told my dad that I was planning to stay, he'll be in the States - "

"You misunderstood, darling. I didn't mean _your_ home. I meant _mine._ _"_

* * *

"Oh my _god,_ I can't believe you talked me into this!" Caroline flopped dramatically back onto the bed in her guest room, groaning heavily for maximum effect. Kol paid no mind to her theatrics, simply biting the head of a licorice snap.

"It wasn't _that_ bad, Forbes."

"It was bad, Kol. Your mother hates me."

Kol took a seat on the edge of the bed, "She does not _hate_ you. She's like that with everybody, really. Finn's the only one who can get a smile out of her and if you met the git you'd know that being like him is not something you want."

Caroline was barely paying attention, more focused on replaying the dinner from hell over and over and over in her mind. It's not something that ever bothers her, her half-blood status; her father had kept more than one secret from his family for most of Caroline's childhood. She hadn't grown up in the wizarding world and getting to play with magic was every eleven year-old's dream, so she didn't think twice about accepting her Hogwarts admission, even as her father tried to warn her that there were prejudices she didn't understand, wars that she'd never had to learn about.

It was fine, mostly. Even as a Slytherin, any one of her housemates who gave her hell usually ended up on the wrong side of a jinx, and for the most part, the pure-blood fanaticism had been driven underground after the second Wizarding War.

Apparently, no one gave the memo to Esther Mikaelson; current matriarch of one of the country's 'distinguished lineages', as she'd so pointedly put it. Esther's disdain was muted but apparent, hidden behind false smiles that never reached her eyes and Caroline was more than content to avoid the woman for the rest of her life.

"I should just stay in here the rest of the break and study," she said into a pillow, yelping when Kol poked her side.

"Don't sulk Sweets, I've got just the thing to cheer you up!"

Caroline seriously doubted it, but looked up anyway, seeing Kol fit to burst.

"How do you feel about a visit to the Ministry?"

It was the only thing he could've said to cheer her up and he knew it. Caroline Forbes was nothing if not a planner, and her current plans included an illustrious career on Level one in the Prime Minister's office. But she'd never actually visited the Ministry before and this was something she couldn't turn down.

"Are you serious?" Caroline asked, sitting upright.

Kol nodded, a self-satisfied grin on his face. "Elijah thought I might like to pop in, take a tour."

Caroline raised a skeptical eyebrow, "Elijah? 'Boring, always-wears-formal-robes, complete prat' Elijah? He wants you to _pop in?_ _"_

"Well, he might have had some encouragement from dear old Mum to persuade me into following in my brothers' footsteps and applying for a Ministry position after graduation."

"And you're…actually considering it?"

"Christ no, but I'm sure there's someone in the Magical Games and Sports Department who can give me tickets to the next World Cup if I namedrop Elijah. So what do you say darling?"

The chance to get out of this house from hell was almost too good to be true and Caroline didn't have to think twice, bouncing across the bed to crush Kol in a hug. "I can't wait!"

* * *

Squeezing her eyes shut, Caroline tossed the knut over her shoulder, hearing the small 'plop' as it landed in the fountain. Smiling to herself, she turned to admire the gold statues once more before a tug on her elbow drew her attention.

"Could you not be such a _tourist?_ _"_ Kol whined, pulling her across the atrium towards the golden gates that separated the bank of lifts. Together they wound their way through the throng of witches and wizards scurrying around, most looking harried, purple floating paper airplanes trailing behind them. Caroline couldn't help herself, she took it in with a gaping mouth, still awed by the wizarding world and everything it was capable of.

"This place is so cool," she said in a hushed whisper as her and Kol crushed into an elevator.

"It's a bore," Kol said flippantly, ignoring the frowns from the people crushed against them. "Perfect for Elijah really."

"What exactly does he do for the Ministry?" asked Caroline as the lift slowly emptied out the higher they went. The smooth voice from the speaker announced the offices for the Minister of Magic and they stepped out into a large foyer with dark paneled walls, plush purple carpets and gleaming mahogany doors. Caroline tried to hide her gawking but it was impossible.

"He's the Advisor to the Minister," Kol explained, rolling his eyes when Caroline's mouth dropped open even wider, if possible.

" _Seriously?!_ "

"Knowing 'Lijah, he's probably connived his way into running the country, but don't tell him I said that," Kol said with a wink, knocking sharply on one of the imposing doors. It opened of its own accord, and he led Caroline into the large room, walls lined to the ceiling with bookshelves but otherwise decorated austerely.

Behind a stately desk sat the oldest Mikaelson brother, Caroline recognized him from the portrait Esther had hung in the foyer of the mansion. She'd assumed that the painting's stiffness was an exaggeration, and even though it barely spoke a word to her, she could swear it was judging her somehow and finding her wanting every time she passed. But finally facing Elijah in person, she could see that the painting was truer to life than she'd thought.

Elijah was better than his mother; Caroline would give him that. But there was a split-second assessment in his eyes that she didn't miss, even though it was quickly covered up with a polite smile as he rose to greet them.

"Miss Forbes, a pleasure to meet you."

Caroline shook his proffered hand, exchanging similar pleasantries. She turned to find Kol but realized that he had bypassed Elijah and gone towards another person that she hadn't even realized was standing in the room.

"Bloody hell Nik, what're you doing up here?" Kol asked, grinning widely.

'Nik' was one of Kol's other brothers, Caroline realized quickly as she took him in. He had dark blonde curls and a dimpled smile that she willed herself not to stare too long at. She knew him from the mansion too, though he didn't occupy quite so prominent a spot as Elijah. In fact, Caroline was pretty sure she only recognized him from a picture Kol had in his room, one of his rare expressions of sentimentality. The brothers had seemed close in it, and Kol definitely seemed more interested to see him, not that Caroline was surprised. This brother had none of Elijah's stiff air, and wore muggle clothes, which shocked her a little but fit with his causal attitude.

As if realizing he had an audience, 'Nik' looked up to meet Caroline's stare, and she barely had time to blush before his lips (very prominent, _not_ that she noticed) curved into a slow smirk as he looked her over.

"Hello love," he said, coming over to join Elijah and extending a hand towards Caroline. "You must be Kol's friend. Klaus Mikaelson."

"Caroline Forbes," she said, shaking it, swallowing thickly when their hands met. A jolt of something went through her, and after seven years in the Wizarding World, Caroline could only describe the feeling as magic. She opened her mouth to say something, anything, but was at a loss for words, staring up at Klaus like an idiot. A throat cleared somewhere to her left, and she finally dropped Klaus's hand and turned her attention back to Elijah, who looked less than impressed.

"Well, since you're both here, was there anything you'd like to see first?" asked Elijah. "Kol mentioned you had some interest in pursuing a career in the Ministry after graduating from Hogwarts."

Caroline brightened up, reaching into her bag to pull out the list of questions she'd already written up, but her face fell when she realized what was missing. "I left my wallet next to the fountain," she moaned, cursing her own stupidity. She shot an apologetic smile at the three brothers and turned on her heel. "I'll just head down and grab it."

"Sure it's still there?" asked Kol skeptically.

"It's charmed against thieves," said Caroline, a little smugly. She couldn't help but noticed the impressed smirk on Klaus's face and it boosted her confidence, especially with Elijah's omnipresent judgment clouding the air.

Kol slipped away from his older brothers, "I'll go with you Sweets, you might get lost."

"Kol, the atrium's just on the fifth floor, I won't get lost-"

"It's your first time here, you shouldn't take chances."

"It's your first time?" Klaus asked, interest piqued.

"Yes it is, so I'll just take Caroline down and we'll be back soon!" said Kol with a small wave as he led Caroline towards the door. He pulled the handle but nothing happened. Frowning, Kol tugged it harder, but the door remained completely steadfast. Caroline was just about to try herself before Kol cursed under his breath and turned them around. They were met with the sight of Elijah leaning against his desk with a bored expression on his face and his wand out, clearing keeping the door locked. Klaus barely restrained a chuckle at the murderous look on his younger brother's face.

" _Elijah,_ _"_ Kol whined, but the eldest Mikaelson was having none of it.

"Kol, you are not here to badger Ludo Bagman into giving you Quidditch tickets."

"I was not-"

"Mother insisted you seriously consider your options, not create havoc in other departments."

"I still need to get my wallet," Caroline said meekly while the brothers locked themselves in a stare-off."

"I'll go with you sweetheart," Klaus offered gallantly, striding forward and pulling out his wand. A quick _Alohomora_ and he'd steered her away from the office, just as an argument between Kol and Elijah started up. Caroline looked behind her, wondering if she should be leaving her friend, but the elevator doors closed on her before she could decide to stay.

"Don't worry about him," Klaus said in response to her silent worries. "Kol's been able to hold his own for as long as I can remember. He'll give Elijah one hell of a headache."

"Sounds like Kol," Caroline said with a faint smile. She was suddenly very aware of the fact that it was just the two of them in that elevator, and unlike the ride up, no one else appeared to be joining them.

"So, what do you do here?" asked Caroline. "Do you work with the Minister too?"

She didn't know what about her question was so funny but Klaus chuckled, a low rumbling sound that made her fidget in anticipation of something she wasn't even sure was coming.

"Hardly. Politics are more Elijah's forte. Finn has his fun in the Obliviator Headquarters - watch your memory when you're around him - but I chose a more unorthodox field of work."

The elevator opened up into the bustle of the atrium and Klaus gently led Caroline towards the fountain where she spotted her bright pink wallet sitting on the ledge. At least one wizard gave her a dirty look as he nursed his hand and Caroline silently thanked her Charms professor for giving her all those extra credit projects.

"I guess we should go rescue Kol," Caroline said, but she lingered, in no real hurry to get back to whatever yelling match her friend was surely in. Klaus noticed her reluctance and he perked up considerably.

"I never did tell you where I worked," he said playfully, a clear invitation in his tone. He offered Caroline his arm and winked. "I might as well show you."

Honestly, Caroline knew she what she shouldn't do. This was Kol's brother, a man she'd just met, and dimples and charm notwithstanding, she had no clue what he was like or capable of. Still…the flutter of magic when he stood close to her was hard to ignore. And it wasn't like she couldn't handle a little flirting. So with a bright smile, she took his arm and let him lead the way.

* * *

 _Level Nine. Department of Mysteries._

Caroline didn't dare step out of the lift. Klaus stood just outside, hands clasped behind her back, watching her with an amused smile but Caroline just flattened her back against the wall and watched the long dark hallway like it was going to close in on her.

"You're an Unspeakable." It was a statement, not a question, and Klaus just laughed softly, nodding in confirmation.

"Indeed I am."

"Why are you…I'm pretty sure I'm not supposed to be in here." Caroline winced, like she expected Ministry agents to appear out the dark and arrest her where she stood, but after a few moments it was still just her and Klaus, and that long dark hallway.

"It's really not all doom and gloom as people would think," he explained, rocking on his heels. "After the mess in '96, there was a push for more transparency."

"I can't just wander around in there Klaus!" she cried.

Klaus waved off her concerns, "You happen to be a guest, who may or may not be considering a position in the department after graduation," he said, innocent as could be. "You _did_ say you were interested in working here."

"On Level One!"

"Always good to keep your options open," said Klaus blithely. "And after the Second War, recruitment's been a bit of a nightmare."

When Caroline still didn't yield to his cajoling, he stepped forward, back into the elevator. "Nothing's going to happen to you, love," he said lowly, eyes intense on her face. "Take a chance, Caroline. I _dare_ you."

Damn. Times like these, Caroline wondered if she wouldn't have been better suited for Gryffindor, because she could never _ever_ turn down a challenge. She wondered fleetingly if Klaus knew that somehow, or if he was just good enough at reading her to know exactly which buttons to press. Holding her head high, she strode past him, down the dimly lit hallway, hearing his footsteps echo behind hers. Caroline was forced to falter when she came to the black door at the end, but without hesitation, Klaus stepped up behind her and reached around, pushing the door open. For a moment they stayed in that position, Caroline acutely aware of Klaus standing so close to her, but she screwed up her courage and entered the hall.

"How do you get around?" she asked, watching each of the twelve new doors in front of her carefully.

"Authorized personnel know the way," Klaus explained, guiding her towards the far right. He led them into what Caroline knew immediately was the Hall of Prophecies and she couldn't contain her awe. The shelves stretched farther than her eyes could see, the orbs holding the prophecies glowing dimly in the dark, hundreds upon thousands of them, as far as her eyes could see. The high vaulted ceilings made her feel so, so small, and unconsciously, Caroline found herself pressing back into the hand Klaus had against her back, the small connection giving her a small amount of comfort.

"Wow." Caroline's voice was no louder than a whisper.

"All the knowledge of the world's seers, in one room," Klaus murmured, close to her ear. "Imagine the possibilities."

"Isn't that your job?"

Klaus came around to stand next to her, staring up at the long rows of shelves. "Don't worry, I've imagined plenty."

There was something oddly wistful about his tone and Caroline turned to look up at his profile, dimly lit by the prophecies around them. He was a million miles away and she took the opportunity to study him, curious about Mikaelson son who didn't warrant a portrait next to his brother's or a position in the Minister's department. It was enough to make her run her mouth and ask every inappropriate question that came to mind, but she bit her tongue, letting the silence hold for just a little more.

"How do you know if there's a prophecy about you in here?" Caroline finally asked.

Klaus brought himself back to the present, looking down at the blonde with a grin. "Why? Imagining yourself as the next 'chosen one'?"

" _No,_ but I wouldn't mind knowing how many NEWTs I'm going to get," Caroline said archly.

Klaus laughed, and the sound echoed through the oppressive darkness, filling the space. It made the large space so much less intimidating, and Caroline couldn't help but join him until they were both beaming at each other.

"I hope you do consider it, you know," he said, soft once again. "Working here would suit you."

"It would?" Caroline asked, hesitantly. Klaus was closer than before and her mouth ran dry, heart beating out of her chest. It was ridiculous, this was a guy she'd just met, but for whatever reason, she was completely rooted to her spot, staring up at him with wide eyes.

"And I know your ambitions are with the Minister's office," Klaus continued, "but if you're up for a challenge, I wouldn't mind working with you here."

He was close. So close that Caroline could stand on her tiptoes and close the gap between them, but flirting was one thing, kissing a near-stranger in the Department of Mysteries was something that was definitely not a good idea, no matter how much she wanted to. And she really, _really_ wanted to, Caroline realized with a jolt and before she could do anything stupid that would ruin friendships and wreck future job possibilities she stepped back, not missing the split second flash of disappointment on Klaus' face.

"I should…I should get back upstairs," Caroline stuttered, stepping away from him clumsily. She turned on her heel and quickly strode towards the Hall's entrance, Klaus silent on her heels.

"Go on love, I'll be right behind you," Klaus said, sounding a little stiff. His attention was taken by a floating paper airplane that was hovering dutifully near the entrance. "Just ask for the exit and it'll appear."

Leaving the Hall of Prophecies behind her, Caroline walked into the antechamber, working on controlling her breathing, She was behaving like an idiot and this could only end badly, which is why the sooner she got out of this department, the better. Before she could even ask aloud, the door farthest from her opened slightly, warm light shining through the crack. Sighing in relief, she hurried towards the exit.

It _definitely_ wasn't the exit.

The room Caroline had somehow stumbled into was the exact opposite of what she'd just left. It was large but bright, something like sunshine warming her face, though it was impossible to tell where that was coming from. The gleaming marble floor reflected the light, and in the center of the large chamber was a fountain, about twice the size of the one in the atrium. There were no statues on this one, and instead of water, a potion with a mother-of-pearl sheen flowed liberally, steam spiraling upwards. If Caroline concentrated, she could smell the faint scent of lavender and it drew her closer. Potions was something she'd always been good at, and it didn't take long to recognize Amortentia for what it was - but something about this was so much stronger than the little batches they'd made in class last year.

"Caroline!"

Klaus's sharp yell snapped her out of her haze, and she froze, realizing that she'd somehow walked right up to the fountain, and her hand was inches from touching the warm potion. Quickly withdrawing her hand, Caroline stepped back, hoping that Klaus would crack another glib joke, but the stunned expression on his face offered no reassurance. He stepped into the room, unable to find words for a moment.

"This is impossible," he whispered finally. "This room is always locked. _Always._ "

"But you work here, right?" asked Caroline, her tone slightly hysterical. "You're an Unspeakable-"

"In the Hall of Prophecies," Klaus cut her off sharply. "This room is barred to me…how did you get in here?"

Caroline didn't like the accusation in his tone, and the fear of getting arrested was back, setting her on edge. "It was already open!"

"That's _impossible!_ _"_

"Apparently not!"

Klaus was definitely about to snap back at her when he suddenly caught sight of something above their heads and his mouth fell open. Caroline followed his line of sight and her own jaw dropped. There was no ceiling that she could see, no source to the warm light. Instead, hundreds upon thousands of red strings criss-crossed the high walls, from one end the chamber to the other. It was like a nest of spider webs, but Caroline couldn't tell what was keeping them up or why they were even there.

"We have to get out of here," Klaus said faintly, even though he kept his gaze fixated on the red strings. Caroline nodded along dumbly, but neither of them made any move to actually leave. It was dangerous, but something kept them both rooted to the spot, and they might have stayed that way for hours if it wasn't for the soft brush Caroline felt against her fingertips.

She finally looked down, and found a dangling red string wrapping itself around her pinky finger. Panicked, Caroline tugged at it, but it only tightened. She couldn't figure out how it had gotten down, but she tugged at the end of it desperately, hoping this wasn't some soul-eating enchantment that no one would ever know how to fix. Finally, the string came down from the mass, long and meandering, its bright red colour stark against the marble floor. It wasn't free, however, and Caroline followed its winding path along the floor, right up to the feet of the man with her.

That was where she found the other end, tied to Klaus.

For a moment, neither of them said a word. Caroline finally worked up the courage to break the silence. "What is this?" she asked, terrified to hear the answer.

Klaus shook his head, "Not a clue, love." He seemed to be about as terrified as she was and Caroline didn't know if that made her feel better or not. Simultaneously, they tugged desperately at the string, trying to break it, but it didn't give an inch. It felt no stronger than ordinary material, but it must have been heavily enchanted because it only seemed to tighten (though oddly enough, it didn't hurt at all.)

"What is this made of?!" Klaus asked in a growl as Caroline tried biting through the knot on her pinky.

"Look, can we just please get out of here?" she pleaded, giving up on trying to get through it. Maybe there was a pair of enchanted scissors somewhere in the Ministry, but she didn't even want to think about the world of trouble they were both in. Klaus was onto her line of thought and grimly led them both out of the room where the door slammed behind them resolutely.

"Alright. We'll have to keep calm, hide this bloody string until we can get to Elijah…" Klaus trailed off, thinking of what his prim and proper older brother would say to this debacle.

"No…we _don_ _'t_."

Klaus frowned, looking down at Caroline who was staring at her hand, flexing her fingers. Her fingers which were now completely absent of strangling red string. He raised his own and found that the string was gone and upon further inspection of the dim antechamber, there was no sign of it lying on the ground to leave evidence of their blunder.

"What the hell?!" asked Caroline, disoriented somewhere between sheer panic and blinding relief. "What was that room?"

"The most enigmatic part of the Department," Klaus answered, wondering at the incredible luck that no one else had come across them. It was _too_ serendipitous - it was magic that he wasn't going to begin to question.

"Tell no one about this," he ordered, receiving a spectacular eye-roll in return.

" _Obviously_ ," said Caroline. "Wasn't about to get myself a one-way ticket to Azkaban, thanks."

Despite everything, her attitude brought a smirk to his face, impressed by her resolve. "I suppose this has soured any job interest you might have."

It was amazing that he had the presence of mind to make jokes, but a small part of Caroline appreciated it. "Let's just get out of here," she said quickly. He nodded, and they managed the rest of their trip up to Level One with no interruption.

Klaus avoided Elijah's pointed stare and Caroline dodged Kol's innuendo laced questions on what had taken them so long. For all intents and purposes, they'd never gone down to Level Nine, and _definitely_ hadn't potentially compromised centuries of research.

All they needed to do was forget it had ever happened.

Unfortunately, it wasn't that easy.

* * *

The dreams didn't start immediately.

Caroline threw herself back into her final term, determined to pass her NEWTs with flying colours, and her rigorous study schedule kept her mind off red strings and Amortentia fountains and doors that were opened when they should only ever be locked. It was only weeks after Easter break that the first nightmare came, ending with her bolting upright in her four-poster bed, grateful for the curtains that kept her from the other girls waking up to see her shaking.

It had been…vivid. So real that she could feel the blows on her face, the anger of the man looming over her. Caroline raised a trembling hand to press against her cheek but it was fine, no trace of the pain that was excruciating just a second ago. And that was nothing compared the terror she had felt against whomever that man was, only that in the throes of that nightmare, she didn't know whether she was going to live or die.

Still shaking, she tried to recount what he'd said or remember the details of his face but it was quickly becoming a blur. None of it made any sense and Caroline was sure she wasn't getting any more sleep that night, but by morning, she'd gone over her Charms notes three times and was completely set on putting odd nightmares behind her and moving on.

Unfortunately, that'd only been the start of it.

Every few nights, the dreams came. More and more scenes that looked like memories that definitely weren't hers, but whenever she tried to grasp onto the threads of them, they maddeningly slipped away. Throwing herself into study was the only thing that helped, and the weeks leading up to exams passed in one sleep-deprived blur.

As much as she tried to hide it, the dark circles under her eyes were only getting worse. Caroline liked to think everybody was too wrapped up in their stress induced NEWT bubbles to care, but trust the one person who didn't care about anything to realize just how out of it she was. Kol bid his time until their last exam was over and everybody was celebrating to link his arm through hers and pull her away to what he knew was her favourite tree near the lake where he wasted no time mincing words.

"You look like shit."

Caroline was too tired to roll her eyes. "Anything else?"

Kol just kept looking her over critically. "I'm serious, Forbes. What in hell's happened to you?"

"It's just exam stress-"

"That's bollocks and you know it," he cut her off sharply. "Seriously, just…tell me what's going on."

He was actually worried, Caroline could hear it in his voice, see it written on his face and that was enough to tell her just how bad things had gotten. Kol didn't get worried about anything.

"I've been having nightmares," she admitted quietly.

Kol nodded, still serious. "You're not going to fail exams Sweets, if that's what's keeping you up at night."

Caroline pursed her lips, looking for a way to tell him what was going on. "These…aren't about exams. They're more like memories."

Kol's mouth pulled downwards, showing uncharacteristic sympathy. "Your dad?"

Caroline gulped down air. "No…I don't know who it is. Everytime I try to remember, I forget."

Kol's brow furrowed. "Look, just go to Madam Pomfrey and tell her you need something to help you sleep. The graduation ceremony is in a week and if you're still having problems after that, then you'll know it's serious."

She accepted his reasoning and took the Bertie Bott's Jellybeans he pulled out of his bag as a way to cheer her up. It was the first real moment of peace she'd felt in weeks and the next few days were a pleasant relief, a sweet-tasting tonic from Madam Pomfrey giving her the reprieve that she needed. She spent her last week exploring Hogwarts with Kol, finally taking the hidden tunnel to Honeydukes and poking her head into empty hallways and classrooms that they'd somehow missed over seven years.

When the night of the graduation ceremony came, Caroline let herself enjoy the feeling of accomplishment, hug and cry her friends, shake hands with all her professors who congratulated her on a certainly bright future.

Sometime during the post-ceremony reception, Caroline wandered away from where her parents were in conversation with Professor Flitwick, and scanned the hall for Kol. She'd notably been avoiding him because she wasn't too excited to see his icy mother again, but not getting a hug from her closest friend after they were new graduates felt wrong. When she found his tall figure he was flanked by his siblings with no sign of Esther anywhere in sight. Caroline beamed in relief and strode up, Kol catching her in a hug easily.

"Congratulations Miss Forbes," Elijah said politely when she turned to face the rest of them.

"Thanks," Caroline said, appreciating that he actually seemed sincere. Rebekah rolled her eyes and another taller brother whom she assumed was Finn just looked bored, but Caroline's attention was drawn to the Mikaelson she'd been unable to put out of her mind, no matter how much she knew she had to.

"Hello Caroline," Klaus said quietly. There was something markedly intense about the way he looked at her, and Caroline found herself caught in his stare. His face looked a little more haggard since the last time she'd seen him (though no less handsome), and there were dark circles under his eyes…similar to hers. The other Mikaelsons started a conversation about what they hoped would be served at the upcoming feast but Caroline kept darting glances at Klaus, only to find him staring back every single time.

They didn't get their moment until everyone was called into the Great Hall for the Graduation Feast. Instead of joining her parents, Caroline was gently pulled into a side hallway and guided towards a small alcove where she finally turned to face Klaus.

It was like being back in the Department of Mysteries, they could only stare at each other and not say a word. Klaus kept his grip on Caroline's arm, and his grip was surprisingly comforting, giving her that same feeling of warmth she'd felt back in the room in the Department of Mysteries. In fact, this was honestly the first time in weeks that Caroline could say she felt completely grounded, content in a way that she knew deep down had nothing to do with exams being over.

"Have you told anyone?" Klaus asked after a moment.

Caroline didn't need him to clarify. "Of course not!" she insisted, a little put off that that was the first thing he said to her. Not that she actually knew what she wanted to hear from him.

Klaus was visibly relieved, but his mind was still preoccupied. "You look…tired," he said diplomatically.

"Gee, you know all the right things to say to a girl."

Klaus pursed his lips to keep in a grin. "Apologies, love. Just making an observation."

Caroline scoffed. "Yeah, well, you're not looking so hot either."

"Have you been looking?"

"Just making an observation."

It was meant to be scathing but there was a playful tilt in her voice that Caroline slipped in before she could help herself. They'd somehow gotten even closer, the air between them crackling with energy, and no matter how much she wanted to, Caroline couldn't look away from him. His hand on her arm was warmer than ever and Caroline wondered what that hand would feel like on her bare skin, cupping her face, pulling her close-

Now _that_ was a dangerous thought.

If the suddenly hungry look in Klaus's eyes was any indication, his mind had gone down the same path. He took the final step towards her so that she was pressed against the wall, Klaus's chest brushing hers. If he dipped his head down just a fraction he would meet her lips and Caroline wished he would.

" _Find a room!_ _"_

The shrill voice jolted Klaus and Caroline out their bubble and they looked over to see a particularly irate painting of a medieval witch scowling at them from the opposite wall.

"Bugger off," Klaus muttered and the painting's subject huffed in annoyance, leaving her frame to undoubtedly spread gossip. If nothing else, Caroline was glad she'd just graduated and didn't have to worry about Hogwarts gossip anymore.

The moment broken, Klaus and Caroline stared sheepishly at each other, wondering what had come over them. Caroline had never been the type of student to get caught fooling around the halls, and Klaus was still practically a stranger to her…not that it changed the weird connection she felt to him, one that made absolutely no sense. She was supposed to be smarter than to lose her head over a sinful smirk, but it seemed so much more serious than that, and Caroline couldn't figure out _why._

As regretful as Klaus looked, he kept a step away from her, though his stare lost none of its heat. "What are your plans?" he asked, tilting his head curiously.

"Well, I'm waiting for my NEWT results."

"And I'm sure you did brilliantly."

Caroline blushed under his confident praise. "Thanks. After that, I'm not really sure."

"I hope our little accident didn't put you off the Ministry?" Klaus asked. He actually looked worried too, and a little regretful.

Caroline laughed softly. "It hasn't…but I'm keeping my options open in case I still get arrested."

"No chance of that love," Klaus assured her with a wink and a grin. "There was no one in the Department that day…I don't know why or how, but everyone seemed to have a reason to be away."

"Wow, how lucky were we?"

Klaus considered her words for a moment. "Luck…that's one possibility."

"What other explanation could there be?" Caroline asked with a frown.

"Magic," he said softly, intense gaze back on her face. "Magic too mysterious for any living wizard to properly comprehend the workings of."

Caroline's breath stuttered as she contemplated the weight of his words. It might have been too much to handle but being near Klaus still gave her that feeling of being tethered and grounded, so that there was no chance of panic taking over.

Laughter nearby drew their attention to the graduation feast taking place and Caroline knew that her parents would be wondering where she went, and it wouldn't take long for Kol to notice his brother and best friend missing together.

"We should get back," she said regretfully.

Klaus sighed and stepped back to let her pass him, falling into step just behind her. Just before they entered the Great Hall, Caroline remembered her earlier question and turned to Klaus once again. "Wait, you never told me why you look so tired."

"Appreciate the concern, love," Klaus said with a smirk.

"Seriously, is this because of what I did back at the Ministry?" Caroline knew it must have given him some stress, but she really didn't want to think she'd caused too much damage.

"It's not that," Klaus said quickly. "Truthfully…I've been having some odd dreams."

* * *

 _Fingers dragged across her skin, light enough to raise goosebumps and tease her just enough to draw sharp breaths, all of it driving Caroline mad. The silk sheets against her back did nothing to cool her down, heat spreading through every limb as a warm mouth wandered her body, leaving hot kisses against her throat, her breasts, her stomach, lower and lower until a_ very _talented tongue was working its way between her folds and circling her clit._

 _She didn_ _'t lift her head to see who this exquisite torturer was, she didn't need to. All she knew was that she had never felt more content, even as the maddening teasing left her hanging just on the precipice of release, her hands fisting the sheets in frustration._

" _Patience, love," a warm voice teased, breath hot against her ear. "We have all the time in the world."_

Caroline bolted upright in bed, panting heavily. Her skin was hot to the touch and her core was _aching._ She didn't need to check to know she was dripping wet. As much as Caroline appreciated that the nightmares had stopped, this was a new kind of torture, waking up every night wet and wanting and no matter what she tried, it wasn't going away. No amount of touching herself could give her relief, and if there was a magical remedy for this kind of frustration, it wasn't one any of her textbooks had ever talked about.

There was only one explanation, and for the umpteenth time, Caroline found herself back in that warm room in the Ministry, hoping that this wasn't an irreversible curse she'd accidentally cast on herself. It was the only way to make sense of any of this, but there was no one she could turn to for help.

Well. That wasn't strictly true.

Even in the solitary darkness of her room back home, Caroline could barely bring herself to acknowledge the occupant of her dreams, the only other person who might be able to shed some light on what was going on. It was ridiculous, she'd met the man all of _twice_ and she'd spent every night of the past month imagining him doing the most sinful things to her body, again and again and _again._

Klaus Mikaelson was ruining her and sooner or later, she was going to snap.

There were two choices: either face Klaus and see if he could help her, or live with this torment forever, and she didn't know how long she could hold out. For tonight, she settled back against her pillows and let her hand slip beneath her sleep shorts, seeking relief that she knew would be impossible to find.

* * *

"Alright Forbes, either tell me what's wrong with you or I throw you in St. Mungos."

Caroline looked up from her ice-cream to see Kol sitting back on the on the bench opposite her, arms crossed and more serious than in the seven years they'd been friends.

"What-what are you talking about?" she asked nervously. She'd been trying so hard to act normal, spending a day in Diagon Alley with Kol was supposed to give her some distraction that could knock her back to normal, but honestly, she'd been distracted and jumpy all day.

Kol looked distinctly unimpressed by her pitiful attempt at deflection. "You're pale, you didn't scold me for jinxing that Muggle who cut us off, and you only ordered one scoop of ice-cream."

"You _jinxed_ a Muggle?!"

"And you were completely oblivious, now are you going to tell me what's wrong? You're not still having those nightmares, are you?"

Caroline wanted to tell him, honestly, but how does one go about telling their best friend you were having sex dreams about their brother? To say nothing of the earlier nightmares, which she could only imagine were intensely private memories.

"Look…it's complicated. I think there's a spell on me."

Kol sat straighter, lips pressed into a hard line. "Who did it?"

"I think I did it to myself," Caroline admitted quietly. "But I know who can help me."

Kol waited with a raised eyebrow and it took a second for Caroline to summon up the courage to ask one little question. "Can I have Klaus's address?"

The look on her friend's face was almost comical. "You want to get in touch with.. _Nik_?" he asked disbelievingly.

Caroline nodded and Kol narrowed his eyes at her. "This is because of that day in the Ministry! I knew you two were gone for two long but I just thought you'd decided to snog him, what the bloody hell happened?!"

"Could you keep your voice down?!" Caroline hissed, all too aware of the other people outside Florean Fortescue's that afternoon.

"Fine. Nik lives near Whitechapel, I can give you the address to his flat if you're desperate. Need me to come with?"

Caroline appreciated the offer, she really did, but shook her head ruefully. "No…this is a trip I have to make alone."

* * *

Caroline didn't know what exactly what she was expecting when she knocked on Klaus's door, and while she waited for him to answer, a thousand doubts ran through her mind. What if he was fine? What if he just had normal dream and anxieties to keep him up at night and a random friend of his little brother's was nothing he was worried about? How was she going to tell a near stranger that she was having dreams of him giving her orgasm after orgasm and that there was a small part of her that was starting to think making those dreams a reality was the only way to get them to stop?

And then - what if he didn't believe her?

It took about thirty seconds for every worst case scenario to go through Caroline's mind, but when the door was finally flung open, it was clear that she had nothing to worry about.

"Caroline?" Klaus asked, voice hoarse. Just the sound of it sent a jolt of pleasure to Caroline's core and she swallowed thickly. The way he looked at her, like a parched man seeing water, told her that her worries were unfounded; he was just as affected as she was.

Well. That was comforting.

"Hey Klaus…can I come in?"

He nodded dumbly, moving aside to let her in. Caroline took a second to look around the flat, for a bachelor, Klaus had good taste. It was mostly dark colours and slightly sparse, but she noticed a small pile of sketchbooks next to a framed picture of his siblings, all of them alternating bickering at each other with smiling towards the camera. It brought a small smile to her face before a throat cleared, drawing her attention back to the man she'd come here to see.

"Why are you here, Caroline?" he asked apprehensively.

Caroline turned to face him and he watched her keenly, that same hunger in his eyes that she'd seen back in Hogwarts, but this time mixed with an edge of desperation that she was very familiar with.

"I need to talk to you…about that day in the Ministry."

Klaus nodded curtly, not looking surprised at all. "Something happened to us." It was a statement, not a question.

"You…you've been having dreams?" Caroline could barely bring herself to meet his eyes and a warm blush spread across her cheeks. If his dreams were _anything_ like hers…she didn't know what to be more concerned by, the thought that he'd been seeing her childhood memories, or the thought that he'd been seeing her sprawled against sheets, begging for him.

When she did brave eye contact, the full-blown lust that she saw told her the latter was definitely worse.

"It started a week after that day," Klaus started softly. "I saw flashes, nothing I could understand. A life that wasn't mine. Someone was leaving - your father, I think. It broke your heart."

Caroline ducked her head, not wanting to drudge up unwanted memories. "I think I saw worse. What your dad did to you…"

A warm hand cupped her cheek, tilting her head up so that Caroline was forced to meet Klaus's eyes again, and for a moment she went breathless at how close he was. The feeling of his hand on her skin caused a tidal wave of relief to crash over her, followed closely by a gnawing hunger for more.

"Let's not rehash the past," Klaus said firmly, thumb stroking the apple of her cheek. "Besides, after I saw you at Hogwarts, the dreams changed." He hesitated and it wasn't hard to guess why.

Caroline didn't care about whatever curse or spell was on them, every inch of her was aching to make those more recent dreams a reality. "Mine changed too," she admitted, licking her lips and taking note of how Klaus's gaze darkened even further.

"And what did they become?" he asked. The husky note in his voice had her skin on fire, and if she thought that the hold he had on her cheek was enough, it quickly became a tease of what she could have if she _just gave in._

So she did.

It had been a long time since Caroline had done anything out of control with her magic, but when she pressed her lips to Klaus's, she swore the lights flickered, just a for a second, a hum of electricity in the air that was soon forgotten as soon as Klaus caught up to what she was doing and instantly pulled her closer, letting his lips devour hers, pressing her body against the nearest wall and meeting her chest to chest, one leg working it's way between hers and Caroline sagged against him, torn between the feeling of satisfaction and the need to divest of the fabric separating them.

Breathless, Klaus managed to pull away, looking down at her with heavy lidded eyes. "What happened to us?"

"Curse, spell-" Caroline trailed off as Klaus found her pulse point, tongue and lips working over the sensitive skin untl she knew he'd left a mark. "Some magic."

"Is this right then?"

His face was still buried in her neck but he stopped his ministrations for a moment and Caroline knew how much that had to kill him. Hell, it nearly killed her. He was probably right to, giving in to magical impulses had a way of working out badly and Caroline didn't know if this was even of their own free will. The thought of never having control again scared her.

Then again, Klaus was right in the same boat with her, and she remembered his smile the first time they met, the way it felt when he took her hand. Magic be damned, they'd figure out the details later, this was not about to be something she passed by.

"This is very, _very,_ right," Caroline said, and he needed no further encouragement.

"In that case love, let's make those dreams a reality, shall we?" He grinned wolfishly, lifting his head and standing to his full height so that he could crowd her against the wall, one hand toying with a stray curl, the other trailing down her side. "I'd like to know if there was any difference though, in what we saw."

"I'm pretty sure we were along the same lines," Caroline said, his trailing fingers teasing her, just like he had in her dreams, enough to drive her mad. For want of something to touch she wrapped her arms around his neck, trying to pull him down again, but where he'd been ravenous just a second ago, somehow he exhibited incredible control, which she was sure was just to fuck with her until she was a begging mess.

"Humour me, sweetheart," he said. His fingers had reached her thigh, pushing up the fabric of her dress, drawing a sharp keening sound from her which had him grinning widely.

"You were just like this," she said through gritted teeth. "Teasing me."

"Good girl," Klaus drawled, finally moving his fingers to rub against the lace covering her slit, smirk widening when he found it drenched. "Tell me more."

Caroline stuttered, not sure if she was even capable of forming coherent sentences, much less what Klaus was asking of her. But when she remained silent he frowned, stilling the slow circles he'd been rubbing against her thong and Caroline nearly cried in frustration.

"Words, love, or I stop," he threatened. It didn't matter that he was hard as a rock against her and probably as desperate for her as she was him, Caroline couldn't take any chances. "You teased me until I was begging for you," she said, throwing all modesty to the wind. "Used your fingers first, but stopped just before I came. Told me to be patient."

Klaus chuckled in her ear, tearing at the lace until it slid down her legs and Caroline wasted no time kicking it off. He gave her no warning as he pushed one finger into her curling it against her and taking great pleasure in the bliss on her face.

" _More,_ please," she pleaded.

Surprisingly, Klaus obliged her, a second finger joining the first, pumping her slowly until she was a panting mess in his arms. Just when her breathing hitched, Klaus pulled his fingers away, watching with amusement as she cried out in indignation, settling for licking the taste of her off his fingers while she watched him with equal parts fury and want.

"You're such an asshole," she muttered, and he just laughed, easily picking her up to wrap her legs around them so that he could walk them to his bedroom, losing shoes along the way.

"You were like this in mine," he said as he pushed her down against the sheets. "Wanton and begging for me. It's a good look for you, love."

Caroline was done listening to him tease her out, she sat up and reached for the Henley he was wearing, pulling it up and off his body, her hands immediately trailing his chest, lips following their path.

"I'm pretty sure you shut up at some point and fucked me in mine," she said impatiently. "I've been waiting for the real thing for weeks."

Two firm hands pushed her down against the pillows and Klaus hovered above her. "Show me," he growled. "All alone and thinking of me, show me what you did."

Caroline didn't need further instruction. The list of things she thought she couldn't do was shrinking by the minute, so without losing eye contact with Klaus, she shimmied out of her thin sundress and threw it somewhere off the bed, watching with some satisfaction as his eyes widened when he realized there was no bra under her dress. Taking a deep breath, she reached up to palm a breast, tweaking a stiff nipple while her other hand reached for her clit, playing with it under the Klaus's heavy watch.

"Nothing helped," Caroline whispered, hoping to break his control. "No matter what I did, I couldn't get off."

"Magic is a mysterious thing," Klaus said idly, but his voice was hoarse and it was clear he couldn't take this himself anymore. Finally, he reached up a hand to replace hers on her breast, kneading the smooth skin and toying with her nipple, his lips closing around the other one. Caroline dropped her head against the pillows and relished the feeling of sweet relief, hands playing with the soft curls at the back of his neck, but his head pulled out of her grasp as he moved lower, drawing a trail of hot kisses over her stomach until he finally reached her center.

When his tongue licked over her slit Caroline's back arched off the bed and she gasped, hands grabbing fistfuls of sheets as his tongue darted inside her, tasting and teasing and driving her closer and closer to a climax he was finally going to deliver. His talented fingers tweaked her clit until she was falling over the edge, coming on his tongue with a small scream.

Her skin was slick with sweat, Klaus had left her completely boneless and she barely registered him kicking off his jeans until he was back over her, kissing her so that she could taste herself on him, skin finally meeting skin from head to toe. "I believe you said I fucked you, in these dreams of yours," he said cheekily. "Suppose I should deliver on that too."

"Only if you want," Caroline replied, just as boldy, but judging by how hard he was against her stomach, it wasn't something he was about to renege on. He wasted no time teasing her entrance this time, positioning himself quickly and burying himself into her in the next second, groaning in ecstasy as he felt her around him.

"You're so bloody tight love," he said through gritted teeth, meeting her lips in another bruising kiss. "Absolutely perfect."

"Klaus, _move._ _"_

He chuckled, something that was quickly becoming her new favourite sound. To his credit, he did move, slowly at first but he worked up to a punishing pace, fucking her into the sheets, toying with her clit to draw out another orgasm for her. The first one had left her so sensitive that it didn't take long, and she felt the tell-tale tightening, and she was shattering around his cock, his movements made the moment last.

He followed her over the edge quickly, groaning into her neck as he came down from his high, neither bothering to move. "Can I assume you'll be spending the night?" he asked wryly, drawing lazy patterns over her stomach.

"Hmm," Caroline hummed contentedly. "I'm definitely not moving for a while."

"Very well love. I intend to go for round two in a bit."

* * *

It was sometime in the early morning, but Caroline couldn't give a damn about the time, not when Klaus was pressed up behind her, an iron grip around her waist. They were finally exhausted, but something had pulled her from sleep, even though she was seconds away from drifting off again. She would have too, had something not caught her eye.

It was faint, just in the corner of her eye, but Caroline swore she saw a flash of red. She raised her head ever so slightly-but it was gone. It hadn't been her imagination though, she was sure of that, there had been something bright red on the duvet, something between her and Klaus. It was gone now, but she'd seen that stark shade before, in the room in the Ministry where the door was supposed to be forever locked, in the room where she and Klaus were never supposed to be in.

Or…maybe they were?

Magic was funny that way.

"Go to sleep love,' Klaus mumbled from somewhere near her shoulder. Caroline didn't hesitate to listen; red strings were something to worry about another time. Whether this was them, or that room, she wasn't going to overthink it. As she slipped back into slumber though, Caroline let her mind wander back into that chamber in the Ministry, the nest of red strings.

All that love in the world. What a beautiful thing.

* * *

 **Hope you enjoyed! And be sure to check out the sequel, 'The Magic that Binds Us'**


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